Many airlines are still using a "significant proportion" of paper tickets despite a deadline to switch to e-tickets by May 31.
A survey by ECTAA, the European agents' association, found that paper tickets represented 10% of an agents, air transport activities.
The survey of carriers in Europe, Canada, South Africa, India and Australia, also found there is "no satisfactory solution for travel agents to issue when e-ticket is not available."
The deadline of May 31 has been imposed by the International Air Transport Association (IATA).
But despite these problems, ECTAA said IATA refused to discuss the matter at the Global Joint Council meeting between IATA, its airline members and agents' representatives in Geneva last week (April 23).
ECTAA, which includes GEBTA, the European business travel agents' association, said many airlines will not have reached 100% e-tickets by the end of the month but there was no satisfactory alternative.
It said agents would be forced to adopt "inefficient and time consuming ticketing procedures" which will "create an unlevel playing field with airlines" which will always be able to issue on their own paper tickets.
ECTAA said that some agents were now taking legal action over the issue.
But in its statement, it said that IATA had refused to "provide any feedback or start any discussion because of the legal action that has been filed against them."
It said it had now formally requested IATA to allow IATA-registered agents to use neutral paper tickets beyond May 31 until "conditions are more appropriate for a total removal of neutral paper tickets."
BTE did approach IATA but received no response.